The broad band laser emission observed from organic dye lasers provides a source of continuously tunable coherent radiation. Tuning of a dye laser was first accomplished in 1967 by Soffer and McFarland by replacing the back reflector of the optical resonant cavity with a rotatable diffraction grating. Since that time other organic dye laser tuning techniques for producing narrowband laser emission have been devised, most of which have been electro-mechanical in design.
The primary disadvantage in using any tuning system that has moving parts, such as a rotatable diffraction grating or electro-mechanical devices, is its limited tuning rate. The present invention is a tuning system having no moving parts. That is, tuning is accomplished by employing stationary components, which are a semiconductor subjected to a strong electric field and a diffraction grating. Intracavity laser beam deflection is responsive to the electric field applied to the semiconductor, and the wavelength retroreflected by the grating is dependent upon the angle of incidence of the deflected intracavity beam on the grating. Thus, the magnitude of the applied field determines the wavelength reflected back into the system, which, in turn, determines the laser wavelength.